Ibuprofin for Muscle Growth?

[805 lb deadlift]

For the last couple of years, many of us who care about muscle growth have tried to limit the amount of NSAIDs (including acetaminophen, which technically isn't an NSAID) we use because research had shown that they inhibit protein synthesis, which is how muscles accrue new size and strength following the training stimulus. NSAIDs tend to have an indiscriminate eicosanoid-depressing action, which includes lowering levels of beneficial eicosanoids as well as the more bothersome inflammatory eicosanoids.

Turns out that research only looked at the acute phase (24 hrs) and not at long-term usage.

A new study shows that over three months, older adults using ibuprofen or acetaminophen grew more muscle as a result of weight training than those on a placebo.

Thirty-six men and women, between 60 and 78 years of age (average age 65), were randomly assigned to daily dosages of either ibuprofen (such as that in Advil), acetaminophen (such as that in Tylenol), or a placebo. The dosages were identical to those recommended by the manufacturers and were selected to most closely mimic what chronic users of these medicines were likely to be taking. Neither the volunteers nor the scientists knew who was receiving which treatment until the end of the study.

All subjects participated in three months of weight training, 15-20 minute sessions conducted in the Human Performance Laboratory three times per week. The researchers knew from their own and other studies that training at this intensity and for this time period would significantly increase muscle mass and strength. They expected the placebo group to show such increases, as its members did, but they were surprised to find that the groups using either ibuprofen or acetaminophen did even better. An earlier study from the laboratory, measuring muscle metabolism (or more precisely, muscle protein synthesis, the mechanism through which new protein is added to muscle), had looked at changes over a 24 hour period. This “acute” study found that both ibuprofen and acetaminophen had a negative impact, by blocking a specific enzyme cyclooxygenase, commonly referred to as COX.

But that study looked at only one day. Over three months, says Dr. Trappe, the chronic consumption of ibuprofen or acetaminophen during resistance training appears to have induced intramuscular changes that enhance the metabolic response to resistance exercise, allowing the body to add substantially more new protein to muscle.

The amount of change was measured in quadricep muscles using Magnetic Resonance Imaging (MRI), the gold standard for determining muscle mass. The researchers now are conducting assays of muscle biopsies taken before and after the three-month period of resistance training, in order to understand the metabolic mechanism of the positive effects of ibuprofen and acetaminophen.

I don't think I'm going to start taking 1,200 mg of ibuprofen each day, but I'm not going to worry about using it when I'm sore anymore.

My guess is that it isn't the anti-inflammatory action of the drugs, since acetaminophen is not a very potent anti-inflammatory, so there must be something else going on. It might work through the suppression of thromboxane, an eicosanoid that causes vasoconstriction. Limiting blood flow into the muscles can prevent nutrients from aiding in the healing of muscle fibers damaged in training, so anything the stops the thromboxanes from constricting blood flow might be aid in strength and muscle gains (but this is also the goal of nitric oxide producing supplements, which have been shown to be useless).

I'll be curious to see what the muscle biopsies reveal.

Tags: fitness, Health, weight training, ibuprofen, acetaminophen, NSAID, muscle growth, eicosanoids, Experimental Biology 2008, American Physiological Society